Without knowing the version of Calibre you are running and what licenses you have available, I can't suggest anything concrete.

There are several coding examples in the Calibre Solutions for Physical Verification manual (calbr_solns_pv_user.pdf). Even if your version of Calibre did not ship with the manual (it has only been around for a couple of years), the solutions apply to most older versions of Calibre as well. The manual is available on SupportNet.

Off-hand, I believe you can code the check using DFM Property.

The example "Verifying Contact Placement for Current Crowding" gives an example of finding regions that contain one or more contacts; I am guessing you can easily modify it for pads instead of contacts, and chip edges instead of source/drain regions.

The example "Counting Contacts in Source/Drain Regions" shows how to output a number per region.

To see whether DFM Property is covered by the DRC license in your version of Calibre, check the Calibre Administrator's Guide. When the DFM commands were first released, they required a Yield Analyzer or Yield Enhancer license, but the ones commonly used for advanced DRC checks like DFM Property became available under the DRC license a year or two after release.